Do apple iPad has a built in flash?

Flash is not supported on the iPad - and as Adobe have announced that they are stopping development on all mobile versions of it, it probably never will be.

Browser apps such as Skyfire, iSwifter, Puffin and Photon 'work' on some sites, but judging by their reviews not all sites. Also some websites have their own apps in the App Store.

If you mean flash light for the camera the answer is also no.

No, the iPad does not feature a built-in LED flash for the camera, nor does it natively support Adobe Flash.